Decoding the secrets of the sacred lotus

University of Adelaide researchers have helped unlock the genetic secrets of one of the world's most unique and culturally significant plants, the sacred lotus.

Among other intriguing properties, the sacred lotus has the ability to generate heat and regulate its temperature like birds and mammals. It has been cultivated as a food crop for more than 7000 years in Asia and is prominent in both Buddhism and Hinduism.

An international team has sequenced and described the sacred lotus genome, now published online in Genome Biology. The paper sheds new light on the evolutionary position of the lotus, one of the world's oldest flowering plants, and facilitates further research into its unusual characteristics.

The lotus is also noted for its long-lived seeds - viable for over 1000 years - and for its water repellency and self-cleaning leaf surfaces. This 'lotus effect' is being adapted for industrial uses.

University of Adelaide plant physiologist Associate Professor Jenny Watling has had a longstanding international collaboration with researchers at the University of Illinois (who led this study), Iwate University in Japan and the University of Wollongong to study the physiology and heat generating properties of the sacred lotus.

"The sacred lotus has huge cultural, religious, economic and medicinal importance and many unusual traits. It also has great scientific significance," says Associate Professor Watling, who is Head of the School of Earth and Environmental Sciences.

"Our work focuses on its incredible ability to generate heat so that it can keep a constant temperature of around 32-34 degrees over a 2-3 day period, while the environmental temperature varies by up to 30 degrees - behaving like a warm-blooded animal."

Associate Professor Watling says the heat generated and the aromas released are particularly attractive to pollinating insects.

"We've found the biochemical pathway the lotus uses for this heat regulation. The plant can switch this pathway on or off, depending on whether it needs more or less heat," she says.

"We've discovered that this pathway depends on a single protein and we now have information about the genes that code for that protein, adding to our knowledge about the mechanisms of lotus thermo-regulation.

"Other flowering plants also have this metabolic pathway, but few use it to the same amazing extent as the lotus."